Ghost lineage

[5] In 1992, an article stated: "These additional entities are taxa [groups] that are predicted to occur by the internal branching structure of phylogenetic trees....

These organisms or species may be closely related to one another, but there are no traces in the fossil records or sediment beds that might shed some light on their origins.

Biologists may infer the existence of ghost lineages by examining sequential stratigraphic units in the fossil record.

The reason for this is their environment, which is deep water near volcanic islands; therefore, these sediments are hard to get to, giving these coelacanths an 80 million year gap or ghost lineage.

[10] Genetic evidence has revealed ghost populations in many species, including modern bonobos and chimpanzees, allopolyploid frogs, polyploid parthenogenetic crayfish, a variety of plants, and humans.